The most common and most likely answer to this crossword clue is the 11 letter word PERPETUALLY
I've seen this crossword clue in The Daily Telegraph
P
E
R
P
E
T
U
A
L
L
Y
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The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PERPETUALLY mean?
PERPETUALLY adverb- Seeming to never end; endlessly; constantly.